Prosthetic liners are well known in the art of the prosthetic devices. It is highly desirable that these liners conform closely to the residual limb, accommodate surface contours and sub-surface bone elements of the residual limb, and provide a comfortable cushion between the residual limb and a hard socket of a prosthesis that is to be fitted over the residual limb.
Special polymeric rubber or elastomer materials, such as silicone compositions, have been formulated as suitable substances for prosthetic liners. These elastomer materials having an appropriate hardness (or softness), elongation, tensile, and other properties, such as bio-inertness (resulting in no skin reaction), have been successfully used for prosthetic liners.
A prosthetic liner which does not lock to a hard socket is generally referred to as a “cushion” liner. Cushion liners are designed to accommodate residual limbs with fragile and exposed tissues, bony prominences prone to pressure peaks, and conical residual limbs. These cushion liners can be geometrically configured to greatly decrease the need for custom-made prosthetic liners. The distal end of these liners often includes a distal end cap embedded into the liner.
A distal end cap may include components made from aluminum or other metal, or rigid plastics such as Nylon. The end cap can create discomfort to the user since it interferes in allowing the liner to conform to the geometry of the limb, and impede pressure distribution of the liner over the residual limb. The end cap may also limit stretchability of the liner.
While effective solutions have been proposed and implemented, it is desirable to improve the comfortibility of such liners or sleeves to increase their ability to conform to irregularities on a residual limb, and accommodate a wider variety of limbs with fewer sizes of liners, while maintaining sufficient strength and durability. Moreover, it is particularly desirable to provide a liner or sleeve arranged to distribute pressure of the liner against a prosthesis while providing superior stretchability over known liners and sleeves.
For the foregoing reasons, there is a need to provide improved liners and sleeves that impart improved conformability, pressure distribution, and stretchability while maintaining sufficient durability and strength for their requisite applications.